The journal of pain : official journal of the American Pain Society
-
Randomized Controlled Trial Multicenter Study
A longitudinal randomized trial of the impact of consistent pain management for infant vaccinations on future vaccination distress.
The objective was to determine if consistent pain management during vaccine injections has a beneficial effect on future infant pain reactivity. This was a multicenter, longitudinal, double-blind, double-dummy, add-on, randomized controlled trial. Healthy infants were randomized to 1 of 4 add-on pain management regimens for all vaccinations in the first year of life: 1) placebo control (standard care), 2) parent video education about infant soothing (video), 3) video and oral sucrose solution (sucrose), 4) video and sucrose and topical liposomal lidocaine (lidocaine). ⋯ Altogether, 352 infants participated; characteristics did not differ among groups (P > .05). Pain scores did not differ among groups during baseline (P = .642), needle injection (P = .739), or recovery (P = .750) phases. In conclusion, there was no evidence of a long-term benefit of consistent use of pain interventions in the first year of life on future infant pain responsivity at 15-month vaccinations.
-
The dorsolateral prefrontal cortex (DLPFC) is a functionally and structurally heterogeneous region and a key node of several brain networks, implicated in cognitive, affective, and sensory processing. As such, the DLPFC is commonly activated in experimental pain studies, and shows abnormally increased function in chronic pain populations. Furthermore, several studies have shown that some chronic pains are associated with decreased left DLPFC gray matter and that successful interventions can reverse this structural abnormality. In addition, studies have indicated that noninvasive stimulation of the left DLPFC effectively treats some chronic pains. In this article, we review the neuroimaging literature regarding the role of the DLPFC and its potential as a therapeutic target for chronic pain conditions, including studies showing the involvement of the DLPFC in encoding and modulating acute pain and studies demonstrating the reversal of DLPFC functional and structural abnormalities after successful interventions for chronic pain. We also review studies of noninvasive brain stimulation of the DLPFC showing acute pain modulation and some effectiveness as a treatment for certain chronic pain conditions. We further discuss the network architecture of the DLPFC, and postulate mechanisms by which DLPFC stimulation alleviates chronic pain. Future work testing these mechanisms will allow for more effective therapies. ⋯ The structure and function of the DLPFC is abnormal in some chronic pain conditions. Upon successful resolution of pain, these abnormalities are reversed. Understanding the underlying mechanisms and the role of this region can lead to the development of an effective therapeutic target for some chronic pain conditions.
-
Claims are made for the validity of some self-report pain scales for 3- and 4-year-old children, but little is known about their ability to use such tools. This systematic review identified self-report pain intensity measures used with 3- and/or 4- year-old participants (3-4yo) and considered their reliability and validity within this age span. The search protocol identified research articles that included 3-4yo, reported use of any pain scale, and included self-reported pain intensity ratings. A total of 1,590 articles were screened and 617 articles met inclusion criteria. Of the included studies, 98% aggregated self-report data for 3-4yo with data for older children, leading to overestimates of the reliability and validity of self-report in the younger age group. In the 14 studies that provided nonaggregated data for 3-4yo, there was no evidence for 3-year-old and weak evidence for 4-year-old children being able to use published self-report pain intensity tools in a valid or reliable way. Preschool-age children have been reported to do better with fewer than the 6 response options offered on published faces scales. Simplified tools are being developed for young children; however, more research is needed before these are adopted. ⋯ Some self-report pain scales have been promoted for use with 3- and 4-year-old children, but this is on the basis of studies that aggregated data for younger and older children, resulting in overestimates of reliability and validity for the preschool-age children. Scales with fewer response options show promise, at least for 4-year-old children.
-
Randomized Controlled Trial Multicenter Study
OPRM1 Methylation Contributes to Opioid Tolerance in Cancer Patients.
Cancer patients in pain require high doses of opioids and quickly become opioid-tolerant. Previous studies have shown that chronic cancer pain as well as high-dose opioid use lead to mu-opioid receptor downregulation. In this study we explore downregulation of the mu-opioid receptor gene (OPRM1), as a mechanism for opioid tolerance in the setting of opioid use for cancer pain. ⋯ We focus on 2 main cells within the cancer microenvironment: the cancer cell and the neuron. We show that targeted re-expression of mu-opioid receptor on cancer cells inhibits mechanical and thermal hypersensitivity, and prevents opioid tolerance, in the mouse model. The resultant analgesia and protection against opioid tolerance are likely due to preservation of mu-opioid receptor expression on the cancer-associated neurons.
-
Placebo analgesia, reductions in pain after administration of an inert treatment, is a well documented phenomenon. We report, to our knowledge, the first demonstration that placebo analgesia can be experienced when a sham analgesic is applied onto a rubber hand. ⋯ During synchronous visuotactile stimulation, pain was experienced on the rubber arm, and the application of the sham analgesic to the rubber arm significantly decreased the severity of reported pain. This shows that experience of the body can modulate expectations and the induction of placebo analgesia.